1. Field of the Invention
The invention relates in general to tubes and in particular to a new and useful tube, especially a pre-pressed tube, composed of a plurality of lengths of tube made up of a thermoplastic synthetic material, each length of tube having at one end a plug-in socket, which is conical to the inside for receiving a plug-in end of the length of tube to be connected.
Tubes or pipe line conduits and especially pre-pressed tubes have a permanent problem in respect to producing a smooth, dense and solid connection of the tubes between the individual lengths of tubes. In general the length of tubes made up of synthetic materials are welded in each other on the building site or in a tube-ditch. However, welding is not possible with pre-press tubes advanced inside of the soil. In both cases a traditional welding of the lengths of tubes is very time-consuming and expensive.